International application, now published as WO 2005/052114 A1 (herein incorporated by reference) describes a container assembly for controlling the rate of oxygen transfer from the atmosphere into a liquid stored in the container comprising:                a container with an oxygen permeability of 50 ml to 300 ml of oxygen per square meter of area of wall, for each 1 mm of thickness of said wall, per 24 hour period at room temperature,        a floating barrier member for providing a permeable barrier to limit oxygen access from the head space in the container to the surface of the liquid.        
Whilst the container assembly described in that application is effective for certain requirements, there is a range of additional requirements which need to be met by developing the basic concept of the original invention further. These include:                increasing the maximum volume, whilst maintaining the correct relationship between surface area of the container and the volume within it,        supporting the polyethylene container, so that its shape is maintained,        elevating the vessel off the ground,        allowing all of the contents to be fully drained through the floor,        allowing the vessel to be lifted and tipped to empty solids components of the contents, by means of a forklift with a rotating head,        safely stacking the filled vessels vertically,        removing the requirement for a floating barrier member when the vessel is filled,        providing a convenient means to add and remove oak wood.        
Accordingly the following is a description of an invention which facilitates one or more of these improvements.